I was playing with Assassin's Creed I, trying to decrypt, change stuff, patch and use it... I wrote a small tool to take care of all the segments/metadata copy/overwrite but still I can't make AC1 work. I starts and then quits to XMB with no errors (using the original EBOOT.BIN makes it hang on black screen).

* Yes, multiMAN patches the PARAM.SFO if required (it will prompt you).
* Yes, the memory patch is the same as in Gaia (I guess)
* To use nethost you have to alter your options.ini file. Check the first page or search for the instructions in this thread.